mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-18 10:01:57 -05:00
34b30ed664
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7654 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
138 lines
3.4 KiB
Fortran
138 lines
3.4 KiB
Fortran
subroutine genwsprlf(msgbits,id,icw,cbb,csync,itone)
|
|
|
|
!Encode a WSPR-LF message, produce baseband waveform and sync vector.
|
|
|
|
include 'wsprlf_params.f90'
|
|
|
|
complex cbb(0:NZ-1)
|
|
complex csync(0:NZ-1)
|
|
real x(0:NZ-1)
|
|
real y(0:NZ-1)
|
|
real pp(N2)
|
|
logical first
|
|
integer*1 msgbits(KK),codeword(ND)
|
|
integer icw(ND)
|
|
integer id(NS+ND)
|
|
integer jd(NS+ND)
|
|
integer isync(48) !Long sync vector
|
|
integer ib13(13) !Barker 13 code
|
|
integer itone(NN)
|
|
integer*8 n8
|
|
data ib13/1,1,1,1,1,-1,-1,1,1,-1,1,-1,1/
|
|
data first/.true./
|
|
save first,isync,twopi,pp
|
|
|
|
if(first) then
|
|
n8=z'cbf089223a51'
|
|
do i=1,48
|
|
isync(i)=-1
|
|
if(iand(n8,1).eq.1) isync(i)=1
|
|
n8=n8/2
|
|
enddo
|
|
|
|
twopi=8.0*atan(1.0)
|
|
do i=1,N2 !Half-sine shaped pulse
|
|
pp(i)=sin(0.5*(i-1)*twopi/N2)
|
|
enddo
|
|
first=.false.
|
|
endif
|
|
|
|
call encode300(msgbits,codeword) !Encode the test message
|
|
icw=2*codeword - 1
|
|
|
|
! Message structure: R1 48*(S1+D1) S13 48*(D1+S1) R1
|
|
! Generate QPSK without any offset; then shift the y array to get OQPSK.
|
|
|
|
! Do the I channel first: results in array x
|
|
n=0
|
|
k=0
|
|
ia=0
|
|
ib=NSPS-1
|
|
x(ia:ib)=0. !Ramp up (half-symbol; shape TBD)
|
|
do j=1,48 !Insert group of 48*(S1+D1)
|
|
ia=ib+1
|
|
ib=ia+N2-1
|
|
n=n+1
|
|
id(n)=2*isync(j)
|
|
x(ia:ib)=isync(j)*pp !Insert Sync bit
|
|
ia=ib+1
|
|
ib=ia+N2-1
|
|
k=k+1
|
|
n=n+1
|
|
id(n)=icw(k)
|
|
x(ia:ib)=id(n)*pp !Insert data bit
|
|
enddo
|
|
|
|
do j=1,13 !Insert Barker 13 code
|
|
ia=ib+1
|
|
ib=ia+N2-1
|
|
n=n+1
|
|
id(n)=2*ib13(j)
|
|
x(ia:ib)=ib13(j)*pp
|
|
enddo
|
|
|
|
do j=1,48 !Insert group of 48*(S1+D1)
|
|
ia=ib+1
|
|
ib=ia+N2-1
|
|
k=k+1
|
|
n=n+1
|
|
id(n)=icw(k)
|
|
x(ia:ib)=id(n)*pp !Insert data bit
|
|
ia=ib+1
|
|
ib=ia+N2-1
|
|
n=n+1
|
|
id(n)=2*isync(j)
|
|
x(ia:ib)=isync(j)*pp !Insert Sync bit
|
|
enddo
|
|
ia=ib+1
|
|
ib=ia+NSPS-1
|
|
x(ia:ib)=0. !Ramp down (half-symbol; shape TBD)
|
|
|
|
! Now do the Q channel: results in array y
|
|
ia=0
|
|
ib=NSPS-1
|
|
y(ia:ib)=0. !Ramp up (half-symbol; shape TBD)
|
|
do j=1,204
|
|
ia=ib+1
|
|
ib=ia+N2-1
|
|
k=k+1
|
|
n=n+1
|
|
id(n)=icw(k)
|
|
y(ia:ib)=id(n)*pp
|
|
enddo
|
|
ia=ib+1
|
|
ib=ia+NSPS-1
|
|
y(ia:ib)=0. !Ramp down (half-symbol; shape TBD)
|
|
y=cshift(y,-NSPS) !Shift Q array to get OQPSK
|
|
cbb=cmplx(x,y) !Complex baseband waveform
|
|
|
|
ib=NSPS-1
|
|
ib2=NSPS-1+64*N2
|
|
do j=1,48 !Zero all data symbols in x
|
|
ia=ib+1+N2
|
|
ib=ia+N2-1
|
|
x(ia:ib)=0.
|
|
ia2=ib2+1+N2
|
|
ib2=ia2+N2-1
|
|
x(ia2:ib2)=0.
|
|
enddo
|
|
csync=x
|
|
|
|
! Map I and Q to tones.
|
|
n=0
|
|
jz=(NS+ND+1)/2
|
|
do j=1,jz-1
|
|
jd(2*j-1)=id(j)/abs(id(j))
|
|
jd(2*j)=id(j+jz)/abs(id(j+jz))
|
|
enddo
|
|
jd(NS+ND)=id(jz)/abs(id(jz))
|
|
itone=0
|
|
do j=1,jz-1
|
|
itone(2*j-1)=(jd(2*j)*jd(2*j-1)+1)/2;
|
|
itone(2*j)=-(jd(2*j)*jd(2*j+1)-1)/2;
|
|
enddo
|
|
itone(NS+ND)=jd(NS+ND) !### Is this correct ??? ###
|
|
|
|
return
|
|
end subroutine genwsprlf
|